/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.nhncorp.neptune.examples.upload.addtablet;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.Partitioner;

public class UploadPartitioner implements Partitioner<WritableComparable, Writable> {
  public static String MAX_KEY_PREFIX = "neptune.tablet.max.rowkey";
  private JobConf jobConf;
  
  public int getPartition(WritableComparable key, Writable value, int numPartitions) {
    String keyStr = key.toString();
    
    int index = keyStr.indexOf("_");
    
    if(index < 0) {
      return -1;
    }
    int partition = Integer.parseInt(keyStr.substring(0, index));
    
    //Reduce에서 split 정보에 대한 
    String attrKey = MAX_KEY_PREFIX + "." + partition;
    
    if(jobConf.get(attrKey) == null) {
      jobConf.set(attrKey, keyStr);
    } else {
      String maxRowKey = jobConf.get(attrKey);
      if(keyStr.compareTo(maxRowKey) > 0) {
        jobConf.set(attrKey, keyStr);
      }
    }
    
    return partition;
  }

  public void configure(JobConf jobConf) {
    this.jobConf = jobConf;
  }
}
